package com.zsy.domain.strategy.service.armory;

import com.zsy.domain.strategy.model.entity.StrategyAwardEntity;
import com.zsy.domain.strategy.model.entity.StrategyEntity;
import com.zsy.domain.strategy.model.entity.StrategyRuleEntity;
import com.zsy.domain.strategy.respository.IStrategyRepository;
import com.zsy.types.enums.ResponseCode;
import com.zsy.types.exception.AppException;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.math.BigDecimal;
import java.math.RoundingMode;
import java.security.SecureRandom;
import java.util.*;

/**
 * @auther Kea
 * @description 策略装配库，负责初始化策略计算
 * @create 2025-01-07 21:44
 */
@Slf4j
@Service
public class StrategyArmoryDispatch implements IStrategyArmory,IStrategyDispatch {
    @Resource
    private IStrategyRepository repository;
    @Override
    public boolean assembleLotteryStrategy(Long strategyId) {
        // 1.查询配置
        List<StrategyAwardEntity> strategyAwardEntities = repository.queryStrategyAwardList(strategyId);
        assembleLotteryStrategy(String.valueOf(strategyId), strategyAwardEntities);

        // 2.权重策略配置 - 适用于 rule_weight 权重规则配置
        StrategyEntity strategyEntity = repository.queryStrategyEntityByStrategyId(strategyId);
        String ruleWeight = strategyEntity.getRuleWeight();
        if (null == ruleWeight) return true;

        // 3.
        StrategyRuleEntity strategyRuleEntity = repository.queryStrategyRule(strategyId, ruleWeight);
        if (null == strategyRuleEntity)
            throw new AppException(ResponseCode.STRATEGY_RULE_WEIGHT_IS_NULL.getCode(), ResponseCode.STRATEGY_RULE_WEIGHT_IS_NULL.getInfo());
        Map<String, List<Integer>> ruleWeightValueMap = strategyRuleEntity.getRuleWeightValues();
        Set<String> keys = ruleWeightValueMap.keySet();
        for (String key : keys){
            List<Integer> ruleWeightValues = ruleWeightValueMap.get(key);
            ArrayList<StrategyAwardEntity> strategyAwardEntitiesClone = new ArrayList<>(strategyAwardEntities);
            strategyAwardEntitiesClone.removeIf(entity -> !ruleWeightValues.contains(entity.getAwardId()));
            assembleLotteryStrategy(String.valueOf(strategyId).concat("_").concat(key), strategyAwardEntitiesClone);
        }

        return true;
    }

    public boolean assembleLotteryStrategy(String Key, List<StrategyAwardEntity> strategyAwardEntities) {
        // 1.获取最小概率值
        BigDecimal minAwardRate = strategyAwardEntities.stream()
                .map(StrategyAwardEntity::getAwardRate)
                .min(BigDecimal::compareTo)
                .orElse(BigDecimal.ZERO);

        // 2.获取概率总和
        BigDecimal totalAwardRate = strategyAwardEntities.stream()
                .map(StrategyAwardEntity::getAwardRate)
                .reduce(BigDecimal.ZERO, BigDecimal::add);

        // 3.用概率总和 % 最小概率值 获取概率范围
        BigDecimal rateRange = totalAwardRate.divide(minAwardRate, 0, RoundingMode.CEILING);

        // 4.生成策略
        ArrayList<Integer> strategyAwardSearchRateTables = new ArrayList<>(rateRange.intValue());
        for (StrategyAwardEntity strategyAward : strategyAwardEntities) {
            Integer awardId = strategyAward.getAwardId();
            BigDecimal awardRate = strategyAward.getAwardRate();
            for (int i = 0; i < rateRange.multiply(awardRate).setScale(0,RoundingMode.CEILING).intValue(); i++) {
                strategyAwardSearchRateTables.add(awardId);
            }
        }

        // 5.乱序
        Collections.shuffle(strategyAwardSearchRateTables);

        // 6.
        HashMap<Integer, Integer> shuffleStrategyAwardSearchRateTables = new HashMap<>();
        for (int i = 0; i < strategyAwardSearchRateTables.size(); i++) {
            shuffleStrategyAwardSearchRateTables.put(i, strategyAwardSearchRateTables.get(i));
        }

        // 7.存储到redis
        repository.storeStrategyAwardSearchRateTables(Key, shuffleStrategyAwardSearchRateTables.size(), shuffleStrategyAwardSearchRateTables);
        return true;
    }

    @Override
    public Integer getRandomAwardId(Long strategyId) {
        int rateRange = repository.getRateRange(strategyId);
        return repository.getStrategyAwardAssembles(String.valueOf(strategyId), new SecureRandom().nextInt(rateRange));
    }

    @Override
    public Integer getRandomAwardId(Long strategyId, String ruleWeightValue) {
        String key = String.valueOf(strategyId).concat("_").concat(ruleWeightValue);
        // 分布式部署下，不一定为当前应用做的策略装配。也就是值不一定会保存到本应用，而是分布式应用，所以需要从 Redis 中获取。
        int rateRange = repository.getRateRange(key);
        // 通过生成的随机值，获取概率值奖品查找表的结果
        return repository.getStrategyAwardAssembles(key, new SecureRandom().nextInt(rateRange));
    }

}
